<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div>
  <h1>登录页面</h1>
  <input type="text" v-model="user.username" placeholder="用户名" @blur="check2">{{info}}<br>
  <input type="password" v-model="user.password" placeholder="密码"><br>
  <input type="button" value="登录" @click="login">
</div>
<script src="https://cdn.bootcdn.net/ajax/libs/axios/0.21.1/axios.min.js"></script>
<script src="https://cdn.staticfile.org/vue/2.2.2/vue.min.js"></script>
<script>
    let v = new Vue({
        el:"body>div",
        data:{
          user:{
            username:"",
            password:""
          },
          info:""
        },
        methods:{
          login(){
            axios.post("/login",v.user).then(function (response) {
              if (response.data==1){
                alert("登录成功!");
                v.info="登录成功!";
                location.href="/";
              }else if (response.data==2){
                alert("密码错误!");
                v.info="密码错误!";
              }else {
                alert("用户名已存在!");
                v.info="用户名已存在!";
              }
            })
          },
          check2(){
            axios.get("/check2?username="+v.user.username).then(function (response) {
                alert(response.data);
                v.info=response.data;
            })
          }
        }
    })
</script>
</body>
</html>